ICC是怎么计算load的

zero_0 · 发表于 2013-11-20 18:26:11

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各位，我在CTS后发现相同的net 的 cap 比 CTS 前都要增加，有些还挺夸张的，但是cell 的位置和fanout 都没有变，所以想请教一下，ICC到底是怎么算load的。

  Point                                     Fanout    Cap    Trans    Incr    Path
  ----------------------------------------------------------------------------------------------
  clock CLK_SD (rise edge)                                              0.00000 0.00000
  clock network delay (ideal)                                           0.00000 0.00000
  u_sdio_host/u_syn/u_ciu_s0_dtw0/meta1_reg/CK (FFSDQHDMX)    0.40000 0.00000 0.00000 r
  u_sdio_host/u_syn/u_ciu_s0_dtw0/meta1_reg/Q (FFSDQHDMX)       0.27346 0.65604 0.65604 f
  u_sdio_host/u_syn/u_ciu_s0_dtw0/dout (net)    3    0.01747          0.00000 0.65604 f
  u_sdio_host/u_syn/u_ciu_s0_dtw0/dout (meta_14)                         0.00000 0.65604 f
  u_sdio_host/u_syn/ciu_s0_dtw[0] (net)             0.01747          0.00000 0.65604 f
  u_sdio_host/u_syn/ciu_s0_dtw[0] (syn)                                  0.00000 0.65604 f
  u_sdio_host/ciu_s0_dtw[0] (net)                   0.01747          0.00000 0.65604 f
  u_sdio_host/u_ciu/ciu_s0_dtw[0] (ciu)                                  0.00000 0.65604 f
  u_sdio_host/u_ciu/ciu_s0_dtw[0] (net)             0.01747          0.00000 0.65604 f
  u_sdio_host/u_ciu/U11/AN (NOR2B1HD1X)                         0.27346 0.00000 *  0.65604 f
  u_sdio_host/u_ciu/U11/Z (NOR2B1HD1X)                         0.19929 0.34666 1.00270 f
  u_sdio_host/u_ciu/n7 (net)                   6    0.02139          0.00000 1.00270 f
  u_sdio_host/u_ciu/u_dat/ciu_dtw (dat)                                  0.00000 1.00270 f
  u_sdio_host/u_ciu/u_dat/ciu_dtw (net)             0.02139          0.00000 1.00270 f
  u_sdio_host/u_ciu/u_dat/U1049/A (NAND2HDLX)                   0.19929 0.00000 *  1.00270 f
  u_sdio_host/u_ciu/u_dat/U1049/Z (NAND2HDLX)                   0.59125 0.43218 1.43488 r
  u_sdio_host/u_ciu/u_dat/n2679 (net)          3    0.01512          0.00000 1.43488 r
  u_sdio_host/u_ciu/u_dat/U2772/A (INVCLKHD1X)                0.59125 0.00000 *  1.43488 r
  u_sdio_host/u_ciu/u_dat/U2772/Z (INVCLKHD1X)                0.22028 0.23400 1.66888 f
  u_sdio_host/u_ciu/u_dat/n2672 (net)          2    0.00929          0.00000 1.66888 f
  u_sdio_host/u_ciu/u_dat/U572/B (NOR2HD2X)                   0.22028 0.00000 *  1.66888 f
  u_sdio_host/u_ciu/u_dat/U572/Z (NOR2HD2X)                   0.20942 0.19869 1.86758 r
  u_sdio_host/u_ciu/u_dat/n2520 (net)          4    0.01676          0.00000 1.86758 r
  u_sdio_host/u_ciu/u_dat/U2765/A (INVCLKHD1X)                0.20942 0.00000 *  1.86758 r
  u_sdio_host/u_ciu/u_dat/U2765/Z (INVCLKHD1X)                0.17502 0.17510 2.04268 f
  u_sdio_host/u_ciu/u_dat/n1025 (net)          2    0.01519          0.00000 2.04268 f
  u_sdio_host/u_ciu/u_dat/U570/A (NOR2HD4X)                   0.17502 0.00000 *  2.04268 f
  u_sdio_host/u_ciu/u_dat/U570/Z (NOR2HD4X)                   0.27260 0.24121 2.28389 r
  u_sdio_host/u_ciu/u_dat/n1042 (net)       20    0.05030          0.00000 2.28389 r
  u_sdio_host/u_ciu/u_dat/U165/A (INVCLKHD3X)                   0.27260 0.00000 *  2.28389 r
  u_sdio_host/u_ciu/u_dat/U165/Z (INVCLKHD3X)                   0.17286 0.18195 2.46584 f
  u_sdio_host/u_ciu/u_dat/n235 (net)          10    0.04234          0.00000 2.46584 f
  u_sdio_host/u_ciu/u_dat/U874/A (NOR2HDLX)                   0.17286 0.00000 *  2.46584 f
  u_sdio_host/u_ciu/u_dat/U874/Z (NOR2HDLX)                   0.68610 0.49487 2.96070 r
  u_sdio_host/u_ciu/u_dat/n2368 (net)          3    0.01297          0.00000 2.96070 r
  u_sdio_host/u_ciu/u_dat/U2575/B (OAI21HDLX)                   0.68610 0.00000 *  2.96070 r
  u_sdio_host/u_ciu/u_dat/U2575/Z (OAI21HDLX)                   0.17725 0.24057 3.20127 f
  u_sdio_host/u_ciu/u_dat/n2519 (net)          1    0.00174          0.00000 3.20127 f
  u_sdio_host/u_ciu/u_dat/U2574/C (OAI21HDLX)                   0.17725 0.00000 *  3.20127 f
  u_sdio_host/u_ciu/u_dat/U2574/Z (OAI21HDLX)                   0.22894 0.19209 3.39337 r
  u_sdio_host/u_ciu/u_dat/n2518 (net)          1    0.00322          0.00000 3.39337 r
  u_sdio_host/u_ciu/u_dat/U2573/A (INVCLKHD1X)                0.22894 0.00000 *  3.39337 r
  u_sdio_host/u_ciu/u_dat/U2573/Z (INVCLKHD1X)                0.10752 0.12362 3.51698 f
  u_sdio_host/u_ciu/u_dat/n2514 (net)          2    0.00521          0.00000 3.51698 f
  u_sdio_host/u_ciu/u_dat/U923/C (OAI211HDLX)                   0.10752 0.00000 *  3.51698 f
  u_sdio_host/u_ciu/u_dat/U923/Z (OAI211HDLX)                   0.44765 0.26075 3.77773 r
u_sdio_host/u_ciu/u_dat/N7739 (net)          2    0.00516          0.00000 3.77773 r
  u_sdio_host/u_ciu/u_dat/dat_en_reg_10_/D (FFSDQHDLX)          0.44765 0.00000 *  3.77773 r
  data arrival time                                                                3.77773

  clock CLK_SD (rise edge)                                              10.00000 10.00000
  clock network delay (ideal)                                           0.00000 10.00000
  clock reconvergence pessimism                                           0.00000 10.00000
  clock uncertainty                                                    -0.35000 9.65000
  u_sdio_host/u_ciu/u_dat/dat_en_reg_10_/CK (FFSDQHDLX)                   0.00000 9.65000 r
  library setup time                                                    -0.28675 9.36325
  data required time                                                                9.36325
  ----------------------------------------------------------------------------------------------
  data required time                                                                9.36325
  data arrival time                                                                -3.77773
  ----------------------------------------------------------------------------------------------
  slack (MET)                                                                      5.58551

这是place之后的report。

  Point                                     Fanout    Cap    Trans    Incr    Path
  ----------------------------------------------------------------------------------------------
  clock CLK_SD (rise edge)                                              0.00000 0.00000
  clk_sd (in)                                                 0.13197 0.06604 0.06604 r
  clk_sd (net)                               1    0.02494          0.00000 0.06604 r
  u_clocks/u_tckmux/BUFCLKHD80X_G1B1I13/A (BUFCLKHD14X)       0.13197 0.00099 *  0.06702 r
  u_clocks/u_tckmux/BUFCLKHD80X_G1B1I13/Z (BUFCLKHD14X)       0.12212 0.19284 0.25986 r
  u_clocks/u_tckmux/clk_sd_G1B1I1 (net)       1    0.11024          0.00000 0.25986 r
  u_clocks/u_tckmux/genblk1_0__HANDINST_MUX/A (MUX2HD7X)       0.12212 0.01182 *  0.27168 r
  u_clocks/u_tckmux/genblk1_0__HANDINST_MUX/Z (MUX2HD7X)       0.19283 0.29169 0.56337 r
  u_clocks/u_tckmux/OUT[0] (net)             1    0.12825          0.00000 0.56337 r
  u_clocks/CTS_CLK_SD_CTO_route_inv539/A (INVHD12X)             0.19283 0.01625 *  0.57962 r
  u_clocks/CTS_CLK_SD_CTO_route_inv539/Z (INVHD12X)             0.11354 0.12469 0.70431 f
  u_clocks/CTS_CLK_SD_CTO_route_inv5391 (net)    1 0.17226          0.00000 0.70431 f
  u_clocks/CTS_CLK_SD_CTO_route_inv540/A (INVHD20X)             0.11667 0.02464 *  0.72895 f
  u_clocks/CTS_CLK_SD_CTO_route_inv540/Z (INVHD20X)             0.09954 0.10451 0.83346 r
  u_clocks/CTS_CLK_SD_CTO_route_inv5401 (net)    2 0.15940          0.00000 0.83346 r
  u_clocks/u_sdclk/genblk1_0__HANDINST_CLKGATE/CK (CLKGTHD20X) 0.10353 0.02511 *  0.85857 r
  u_clocks/u_sdclk/genblk1_0__HANDINST_CLKGATE/Z (CLKGTHD20X) 0.24768 0.54587 1.40445 r
  u_clocks/u_sdclk/GCLK[0] (net)             11    0.48832          0.00000 1.40445 r
  BUFCLKHD16X_G3B2I1/A (BUFCLKHD30X)                            0.26163 0.07268 *  1.47713 r
  BUFCLKHD16X_G3B2I1/Z (BUFCLKHD30X)                            0.09758 0.22524 1.70237 r
  GCLK_G3B1I1[0] (net)                      14    0.23241          0.00000 1.70237 r
  CTS_CLK_SD_CTO_delay547/A (BUFCLKHD40X)                      0.09758 0.01138 *  1.71376 r
  CTS_CLK_SD_CTO_delay547/Z (BUFCLKHD40X)                      0.05165 0.13526 1.84902 r
  CTS_CLK_SD_CTO_delay5471 (net)             3    0.08417          0.00000 1.84902 r
  u_sdio_host/BUFCLKHD3X_G3B1I10/A (BUFCLKHD3X)                0.05165 0.00362 *  1.85263 r
  u_sdio_host/BUFCLKHD3X_G3B1I10/Z (BUFCLKHD3X)                0.40983 0.33944 2.19208 r
  u_sdio_host/GCLK_G3B2I10[0] (net)          29    0.13436          0.00000 2.19208 r
  u_sdio_host/u_syn/u_ciu_s0_dtw0/meta1_reg/CK (FFSDQHDMX)    0.40983 0.00406 *  2.19613 r
  u_sdio_host/u_syn/u_ciu_s0_dtw0/meta1_reg/CK (FFSDQHDMX)    0.40983 0.00000 2.19613 r
  u_sdio_host/u_syn/u_ciu_s0_dtw0/meta1_reg/Q (FFSDQHDMX)       0.45706 0.73093 2.92707 r
  u_sdio_host/u_syn/u_ciu_s0_dtw0/dout (net)    3    0.02159          0.00000 2.92707 r
  u_sdio_host/u_syn/u_ciu_s0_dtw0/dout (meta_14)                         0.00000 2.92707 r
  u_sdio_host/u_syn/ciu_s0_dtw[0] (net)             0.02159          0.00000 2.92707 r
  u_sdio_host/u_syn/ciu_s0_dtw[0] (syn)                                  0.00000 2.92707 r
  u_sdio_host/ciu_s0_dtw[0] (net)                   0.02159          0.00000 2.92707 r
  u_sdio_host/u_ciu/ciu_s0_dtw[0] (ciu)                                  0.00000 2.92707 r
  u_sdio_host/u_ciu/ciu_s0_dtw[0] (net)             0.02159          0.00000 2.92707 r
  u_sdio_host/u_ciu/U11/AN (NOR2B1HD1X)                         0.45706 0.00039 *  2.92746 r
  u_sdio_host/u_ciu/U11/Z (NOR2B1HD1X)                         4.81584 3.00256 5.93002 r
  u_sdio_host/u_ciu/n7 (net)                   6    0.27168          0.00000 5.93002 r
  u_sdio_host/u_ciu/u_dat/ciu_dtw (dat)                                  0.00000 5.93002 r
  u_sdio_host/u_ciu/u_dat/ciu_dtw (net)             0.27168          0.00000 5.93002 r
  u_sdio_host/u_ciu/u_dat/U1008/A (NAND3HD2X)                   4.81584 0.07324 *  6.00325 r
  u_sdio_host/u_ciu/u_dat/U1008/Z (NAND3HD2X)                   1.31342 1.70674 7.70999 f
  u_sdio_host/u_ciu/u_dat/n2177 (net)       10    0.11746          0.00000 7.70999 f
  u_sdio_host/u_ciu/u_dat/U2771/A (NOR2HD3X)                   1.31342 0.01017 *  7.72016 f
  u_sdio_host/u_ciu/u_dat/U2771/Z (NOR2HD3X)                   0.69356 0.70214 8.42229 r
  u_sdio_host/u_ciu/u_dat/n2369 (net)          3    0.08960          0.00000 8.42229 r
  u_sdio_host/u_ciu/u_dat/U2575/A (OAI21HDLX)                   0.69356 0.00034 *  8.42263 r
  u_sdio_host/u_ciu/u_dat/U2575/Z (OAI21HDLX)                   0.26622 0.32614 8.74877 f
  u_sdio_host/u_ciu/u_dat/n2519 (net)          1    0.00408          0.00000 8.74877 f
  u_sdio_host/u_ciu/u_dat/U2574/C (OAI21HDLX)                   0.26622 0.00009 *  8.74886 f
  u_sdio_host/u_ciu/u_dat/U2574/Z (OAI21HDLX)                   0.36853 0.23581 8.98468 r
  u_sdio_host/u_ciu/u_dat/n2518 (net)          1    0.00377          0.00000 8.98468 r
  u_sdio_host/u_ciu/u_dat/U2573/A (INVCLKHD1X)                0.36853 0.00015 *  8.98483 r
  u_sdio_host/u_ciu/u_dat/U2573/Z (INVCLKHD1X)                0.40561 0.36817 9.35300 f
  u_sdio_host/u_ciu/u_dat/n2514 (net)          2    0.04094          0.00000 9.35300 f
  u_sdio_host/u_ciu/u_dat/U923/C (OAI211HDLX)                   0.40561 0.00252 *  9.35552 f
  u_sdio_host/u_ciu/u_dat/U923/Z (OAI211HDLX)                15.60862 7.64548 17.00100 r
  u_sdio_host/u_ciu/u_dat/N7739 (net)          2    0.31866          0.00000 17.00100 r
  u_sdio_host/u_ciu/u_dat/dat_en_reg_10_/D (FFSDQHDLX)       15.60862 0.10834 * 17.10933 r
  data arrival time                                                                17.10933

  clock CLK_SD (rise edge)                                              10.00000 10.00000
  clk_sd (in)                                                 0.13197 0.06604 10.06604 r
  clk_sd (net)                               1    0.02494          0.00000 10.06604 r
  u_clocks/u_tckmux/BUFCLKHD80X_G1B1I13/A (BUFCLKHD14X)       0.13197 0.00099 * 10.06702 r
  u_clocks/u_tckmux/BUFCLKHD80X_G1B1I13/Z (BUFCLKHD14X)       0.12212 0.19284 10.25986 r
  u_clocks/u_tckmux/clk_sd_G1B1I1 (net)       1    0.11024          0.00000 10.25986 r
  u_clocks/u_tckmux/genblk1_0__HANDINST_MUX/A (MUX2HD7X)       0.12212 0.01182 * 10.27168 r
  u_clocks/u_tckmux/genblk1_0__HANDINST_MUX/Z (MUX2HD7X)       0.19283 0.29169 10.56337 r
  u_clocks/u_tckmux/OUT[0] (net)             1    0.12825          0.00000 10.56337 r
  u_clocks/CTS_CLK_SD_CTO_route_inv539/A (INVHD12X)             0.19283 0.01625 * 10.57962 r
  u_clocks/CTS_CLK_SD_CTO_route_inv539/Z (INVHD12X)             0.11354 0.12469 10.70431 f
  u_clocks/CTS_CLK_SD_CTO_route_inv5391 (net)    1 0.17226          0.00000 10.70431 f
  u_clocks/CTS_CLK_SD_CTO_route_inv540/A (INVHD20X)             0.11667 0.02464 * 10.72895 f
  u_clocks/CTS_CLK_SD_CTO_route_inv540/Z (INVHD20X)             0.09954 0.10451 10.83346 r
  u_clocks/CTS_CLK_SD_CTO_route_inv5401 (net)    2 0.15940          0.00000 10.83346 r
  u_clocks/u_sdclk/genblk1_0__HANDINST_CLKGATE/CK (CLKGTHD20X) 0.10353 0.02511 * 10.85857 r
  u_clocks/u_sdclk/genblk1_0__HANDINST_CLKGATE/Z (CLKGTHD20X) 0.24768 0.54587 11.40445 r
  u_clocks/u_sdclk/GCLK[0] (net)             11    0.48832          0.00000 11.40445 r
  u_sdio_host/u_ciu/u_dat/clk_gate_dat_en_reg_0/latch/CK (CLKGTPHD8X)  0.28050  0.11198 * 11.51643 r
  u_sdio_host/u_ciu/u_dat/clk_gate_dat_en_reg_0/latch/Z (CLKGTPHD8X)  0.25636  0.59001 12.10644 r
  u_sdio_host/u_ciu/u_dat/clk_gate_dat_en_reg_0/ENCLK (net) 16  0.21332  0.00000  12.10644 r
  u_sdio_host/u_ciu/u_dat/dat_en_reg_10_/CK (FFSDQHDLX)       0.25778 0.03361 * 12.14005 r
  clock reconvergence pessimism                                           0.00000 12.14005
  clock uncertainty                                                    -0.35000 11.79005
  u_sdio_host/u_ciu/u_dat/dat_en_reg_10_/CK (FFSDQHDLX)                   0.00000 11.79005 r
  library setup time                                                    -3.08140 8.70866
  data required time                                                                8.70866
  ----------------------------------------------------------------------------------------------
  data required time                                                                8.70866
  data arrival time                                                                -17.10933
  ----------------------------------------------------------------------------------------------
  slack (VIOLATED)                                                                -8.40068
这是CTS后的。

比如说红色那条net，为什么cap会相差那么远，三个cell的位置都没有变，u_sdio_host/u_ciu/u_dat/U923 (OAI211HDLX)和另外两个cell隔着hardmacro。

liqiang998 · 发表于 2013-11-21 15:01:04

cts后面的有没有做route?

小干爹z2z · 发表于 2013-11-21 15:36:01

本帖最后由小干爹z2z 于 2013-11-21 15:39 编辑

你先用report_delay_calculation -from u_sdio_host/u_ciu/u_dat/U923/C -to u_sdio_host/u_ciu/u_dat/U923/Z
看看两个有任何不一样，应该是CTS 之后u_sdio_host/u_ciu/u_dat/U923/Z 端cap 变大了
然后你就要看u_sdio_host/u_ciu/u_dat/U923/Z connectivity ，可能不只是连了一个reg，其他的cell 可能在CTS 时被relocation了，甚至连接这个端口的cell中有些是clock path 上 CTS 就动作更大了。
距离远了 cap 就大了 delay就很大了
不过这种不用担心你继续下一步 clock_opt -only_psyn 可以把它修掉的

以上言论不代表本台立场

zero_0 · 发表于 2013-11-22 09:12:52

回复 2# liqiang998

没有的

zero_0 · 发表于 2013-11-22 09:15:48

回复 3# 小干爹z2z

我确定没有任何cell relocation，因为我为了验证这个把它们都 set dont touch 了，谢谢你的指导。

小干爹z2z · 发表于 2013-11-22 10:12:00

回复 5# zero_0

你确定u_sdio_host/u_ciu/u_dat/U923/Z 这个端口接的所有cell 都没有变化？不可能无缘无故就cap 变大的

liqiang998 · 发表于 2013-11-22 15:07:53

红色的那条net有两个fanout,另一条负载看过没？还是没有变化吗？
还有就是你place 和cts的环境有没有什么不同，sdc和相关setting有没有差别？
你可以试试分别报出同一个pin的load（place 和cts）,看看详细报告

[求助] ICC是怎么计算load的

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